Stupid (but quick) question about 8-pin CPU connectors

[Ken90630]

Okay, I'm embarrassed to be asking this, but since I don't know the answer, here goes:

I'm looking to do a new build for a friend, using this Gigabyte motherboard:

http://www.newegg.com/Product/Product.aspx?Item=N82E16813128394

Instead of the extra old-style 4-pin CPU connector, it has an 8-pin one. The PSU I'm planning to use, a Seasonic S12-II 430, just has a 4-pin plug.

I'm sure this has been asked a million times before, but since I'm only planning to use an Athlon II X2 CPU (65W Regor @ 2.8GHz, dual core), can I use that PSU and just plug its 4-pin plug into the 8-pin connector on the mobo? Or do I have to use a PSU with an 8-pin plug? I read somewhere that as long as you're not running a quad-core CPU, the 4-pin plug is okay to use.

TIA, and apologies for asking something I should know by now.

 

[BTA]

Not stupid, I ran into that too and wasn't sure.

I just installed a Gigabyte intel board and my PSU only has the 4pin as well. It works fine. In the manual it describes that it works fine that way (sorta...it's worded terribly).

The 4pin will just go into one side of the plug, and it should only fit in one way.

In fact I'm running a Q9400 with just the 4pin. I don't overclock though.

 

[heyheybooboo]

Check the manual --- if you only use 4-pin make sure you only use the 20-pin main power (don't hook up the '+4-pin').

Did that make sense?



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[Mir96TA]

Perhaps do you need this

 

[BTA]

Jesus you two are retarded. He's not talking about 20pin vs 24pin main motherboard power plugs, and he's not talking about a friggin video card power plug. He's talking about the 8pin CPU power connector...which you can see on board if you actually looked at the pictures of the motherboard he linked.

Ken just plug in the 4pin. It only goes in one way, it wont fry anything.

 

[Gillbot]

Jesus you two are retarded. He's not talking about 20pin vs 24pin main motherboard power plugs, and he's not talking about a friggin video card power plug. He's talking about the 8pin CPU power connector...which you can see on board if you actually looked at the pictures of the motherboard he linked.

Ken just plug in the 4pin. It only goes in one way, it wont fry anything.

It'll work fine with the 4 pin. It'll only go in one way. Also, I'm moving this to PSU's as that's where you'll likely get more and better answers.

AT Mod
Gillbot

 

[VirtualLarry]

Check the manual --- if you only use 4-pin make sure you only use the 20-pin main power (don't hook up the '+4-pin').
Did that make sense?
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No, that makes no sense. If you have a 24-pin (20+4) ATX power, and the mobo has a 24-pin ATX power, then always hook up both parts of the connector.

The ATX12V being 4-pin or 8-pin for the 12V line is independent of the 24-pin ATX connector.

 

[Painman]

You'd think that the thread title, "Stupid (but quick) question about 8-pin CPU connectors"

would be sufficiently explanatory...

8 pin CPU connectors used to be just a server board thing, but with power hungry Quads and such for the desktop, we now see them even on mini-ATX boards like the one posted.

Likewise, in years past, you had to buy an EPS style power supply to get the 8 pin CPU power plug, but now they're commonplace.

The Enermax EPS PSU I recently retired has such an 8 pin plug. It came with an adapter to turn it into a 6 pin PCI-E power lead. That's what I used it for, up until I got my P5Q board.

 

[Ken90630]

Thanks, all. So basically it's only necessary to use an 8-pin CPU plug (on the PSU) if running a quad-core processor, right?

Thanks again for all the replies. I appreciate it.

 

[Swivelguy2]

It has more to do with the TDP of the CPU than with the number of cores.

 

[Gillbot]

Thanks, all. So basically it's only necessary to use an 8-pin CPU plug (on the PSU) if running a quad-core processor, right?

Thanks again for all the replies. I appreciate it.

no

It has more to do with the TDP of the CPU than with the number of cores.

exactly, but you should hook it up no matter what

 

[Ken90630]

Ah, okay. What I meant to say, and probably could've phrased a little better, is that for the most part, the CPUs drawing enough wattage on the 12V rail to warrant the 8-pin PSU connector are typically the quad-core CPUs. Would that be a fair generalization, excluding some high-end power-hungry dual core CPUs?

Along the same lines, would it be fair to say that, generally speaking, 89W-or-less CPUs are gonna be okay with just a 4-pin connector off the PSU (plugged into the ATX12V connector on the mobo)? All assuming, of course, no other inordinate, extreme draws (like high-end vid cards) on the 12V rail.

 

[Gillbot]

As I said earlier, I have used many board/PSU/CPU combos with only the 4 pin AUX connector and have not had a problem even with "decent" video cards and quad cores. I wouldn't go out and buy a PSU just for the 8 pin, but if you need to upgrade anyway, might as well get one.

Honestly, as long as the PSU can support what you plan on running I wouldn't worry about it. You are likely just overthinking it.

 

[Ken90630]

As I said earlier, I have used many board/PSU/CPU combos with only the 4 pin AUX connector and have not had a problem even with "decent" video cards and quad cores. I wouldn't go out and buy a PSU just for the 8 pin, but if you need to upgrade anyway, might as well get one.

Honestly, as long as the PSU can support what you plan on running I wouldn't worry about it. You are likely just overthinking it.

Got it. You're probably right (about the overthinking). Thanks again for the education. :thumbsup:

 

[CraigRT]

As I said earlier, I have used many board/PSU/CPU combos with only the 4 pin AUX connector and have not had a problem even with "decent" video cards and quad cores. I wouldn't go out and buy a PSU just for the 8 pin, but if you need to upgrade anyway, might as well get one.

Honestly, as long as the PSU can support what you plan on running I wouldn't worry about it. You are likely just overthinking it.

It's a question I was wondering too. As I'm planning to upgrade to an i5 fairly soon, yet keeping my S12 600W PSU, as the rest of my system isnt that much, the actual output will be more than enough, I too was just not sure if I had to get a PSU with an 8pin connector. At least now I know I can just try my PSU and if I end up needing more power, the new PSU will have the 8pin anyway..

 

[Gillbot]

It's a question I was wondering too. As I'm planning to upgrade to an i5 fairly soon, yet keeping my S12 600W PSU, as the rest of my system isnt that much, the actual output will be more than enough, I too was just not sure if I had to get a PSU with an 8pin connector. At least now I know I can just try my PSU and if I end up needing more power, the new PSU will have the 8pin anyway..

Never assume the new one will have the 8-pin. Many places are still selling units that do not have the 4-pin, let alone an 8-pin.

 

[CraigRT]

Never assume the new one will have the 8-pin. Many places are still selling units that do not have the 4-pin, let alone an 8-pin.

Sorry, Didn't mean lead on that I would assume, but if I had to buy new, I'd ensure it had the 8 pin connector... Is all I'm saying.